Video communication systems span a variety of applications. One such application is videoconferencing. Videoconferencing typically involves the real-time sharing of video along with audio, graphics and/or data information between two or more terminals over a communications channel. A videoconferencing session may involve merely a video-enabled telephone call between two friends or, in a more complex application, a multi-way call among corporate boardrooms with advanced camera control and with sharing of data applications such as word processors and spreadsheets and using ISDN digital lines or T1 lines for communication.
Videoconferencing technology has been evolving very rapidly. The evolution began with a number of proprietary products, offered by various vendors and communicatively incompatible with each other. As the demand for equipment compatibility grew, vendors and scientific experts began to cooperate and, through a standards body such as the International Telecommunications Union (ITU), industry standards have been and are being adopted. This has typically involved the effort of an industry-wide consortium, such as the International Multimedia Teleconferencing Consortium (IMTC), to iron out implementation details of the standards, agree on the interpretation of sections of the standards that are unclear, and test each of the vendor's products against those provided by other vendors.
Once a baseline level of interoperability has been established, the vendors proceed to bring their standards-compliant products to market, and continue to add their own features to gain competitive advantage. While preserving standards compliance, the vendors differentiate their products from those of other vendors based on price, video/audio quality, and ease-of-use. The mass consumer market demands that such products provide audio/video quality with insubstantial communication-related delays and at extremely low costs. Accordingly, such demands have been difficult to meet.